Preventing Outages under Coordinated Cyber-Physical Attack with Secured PMUs

TL;DR

This paper introduces a novel approach to prevent outages caused by coordinated cyber-physical attacks by optimizing the placement of secured PMUs, reducing the number needed for effective defense in power grids.

Contribution

It formulates a new PMU placement problem for outage prevention as a bi-level MILP and proposes iterative and heuristic algorithms for efficient solutions, extending to AC power flow models.

Findings

Significantly reduces the number of PMUs needed for outage prevention.

Effective on large-scale power grid systems like IEEE 300-bus.

Demonstrates practical applicability through extensive simulations.

Abstract

Due to the potentially severe consequences of coordinated cyber-physical attacks (CCPA), the design of defenses has gained significant attention. A popular approach is to eliminate the existence of attacks by either securing existing sensors or deploying secured PMUs. In this work, we improve this approach by lowering the defense target from eliminating attacks to preventing outages and reducing the required number of PMUs. To this end, we formulate the problem of PMU Placement for Outage Prevention (PPOP) under DC power flow model as a tri-level non-linear optimization problem and transform it into a bi-level mixed-integer linear programming (MILP) problem. Then, we propose an alternating optimization framework to solve PPOP by iteratively adding constraints, for which we develop two constraint generation algorithms. In addition, for large-scale grids, we propose a polynomial-time heuristic algorithm to obtain suboptimal solutions. Next, we extend our solution to achieve the defense goal under AC power flow model. Finally, we evaluate our algorithm on IEEE 30-bus, 57-bus, 118-bus, and 300-bus systems, which demonstrates the potential of the proposed approach in greatly reducing the required number of PMUs.